Initial starting device and method of semiconductor transformer

Abstract

The invention relates to an initial starting device and method of a semiconductor transformer. The initial starting device of the semiconductor transformer includes: a plurality of power conversion unit modules connected in series with each other; and a synchronization controller which provides a synchronization signal with a set period to the plurality of power conversion unit modules, so that the plurality of power conversion unit modules act according to the synchronization signal. When each of the power conversion unit modules is not in operation, it is possible to determine the detected synchronization signal as a start-up signal and start up the power conversion unit modules.

Description

Technical Field

[0001] The present invention relates to an initial start-up apparatus and method for a semiconductor transformer, and more specifically, to an initial start-up apparatus and method for a semiconductor transformer comprising a plurality of series-connected modules. Background Technology

[0002] Power transformers play a crucial role in power systems by transforming voltage at various points, such as transmission, distribution, and substation. However, existing power transformers directly transform low-frequency AC voltage, resulting in large size, heavy weight, and an inability to perform input / output control.

[0003] To address the problems of existing power transformers, the solid-state transformer (SST) has been proposed. That is, compared to existing power transformers, the power conversion device in a semiconductor transformer is configured in a more efficient manner. Such semiconductor transformers, through DC links, can be applied to various technologies such as renewable energy, DC power distribution, and electric vehicle charging.

[0004] In particular, besides voltage transformation, semiconductor transformers can perform multiple functions such as AC / DC power conversion, power factor and harmonic control, and by using high-frequency transformers, their size and weight can be significantly reduced compared to existing power transformers. Furthermore, while individual SST units cannot input high voltages due to semiconductor switching capacity limitations, modular SST units connected in series can input high voltages.

[0005] The applicant's patent application No. 10-2022-0149064 (published on November 8, 2022) describes that semiconductor transformer modules can be connected in series or in parallel, or can be connected in a mixture of series and parallel.

[0006] When semiconductor transformer unit modules are connected in parallel, the system can operate stably even if the modules do not start at the same time. However, when connected in series, the converted power needs to be converted to the next stage in sequence, so it is necessary to control the start-up time of each module.

[0007] However, if the series-connected SST modules fail to start or experience a startup delay for various reasons, the entire semiconductor transformer system will be unable to be driven or will be driven unstably.

[0008] This can be understood as the fact that the actions of individual unit modules connected in series will affect the performance of adjacent unit modules. Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] In view of the problems of the prior art, the problem to be solved by the present invention is to provide an initial start-up device and method for a semiconductor transformer that can start up a plurality of unit modules connected in series with each other simultaneously without using additional devices.

[0011] Technical solutions to the problem

[0012] To address the aforementioned technical challenges, an initial startup device for a semiconductor transformer according to one aspect of the present invention may include: a plurality of power conversion unit modules connected in series with each other; and a synchronization controller that provides a synchronization signal with a set period to the plurality of power conversion unit modules, causing the plurality of power conversion unit modules to operate according to the synchronization signal; each power conversion unit module, when not in operation, may determine the detected synchronization signal as a startup signal and start up.

[0013] In an embodiment of the present invention, the power conversion unit module may include a rectifier and a converter to convert power, and may include a drive unit that charges the link capacitor between the rectifier and the converter during startup.

[0014] In this embodiment of the invention, the driving unit can control the switching of the rectifier or the switching of the converter according to the synchronization signal.

[0015] In this embodiment of the invention, the driving unit can charge the link capacitor by controlling the rectifier.

[0016] In this embodiment of the invention, a charging circuit may also be included, which charges the link capacitor according to the control of the driving unit.

[0017] Furthermore, another aspect of the present invention provides an initial startup method for a semiconductor transformer, comprising a plurality of power conversion unit modules connected in series with each other and a synchronization controller that synchronizes the plurality of power conversion unit modules by providing a synchronization signal with a set period to the plurality of power conversion unit modules. This initial startup method may include: determining whether there is an input of a synchronization signal from the synchronization controller in each of the plurality of power conversion unit modules; confirming whether the plurality of power conversion unit modules are currently in operation if there is an input of a synchronization signal, and determining that if they are in operation, it is a synchronization signal; and determining that if they are not in operation, it is a startup command to start each of the power conversion unit modules, and starting each of the power conversion unit modules.

[0018] In this embodiment of the invention, each of the power conversion unit modules includes a link capacitor connecting the rectifier and the converter, and the power conversion unit module can charge the link capacitor upon startup.

[0019] In this embodiment of the invention, when the synchronization signal is input, if each of the power conversion unit modules is in operation, the power can be converted synchronously with the synchronization signal.

[0020] Invention Effects

[0021] In the semiconductor transformer of the present invention, in which multiple unit modules are connected in series to convert high-voltage AC power into low-voltage AC or low-voltage DC power, a start signal is loaded onto the synchronization signal of each module and sent, thereby starting multiple unit modules simultaneously, thus achieving the effect of stable start-up of the semiconductor transformer. Attached Figure Description

[0022] Figure 1 This is a block diagram of the initial start-up device for a semiconductor transformer according to a preferred embodiment of the present invention.

[0023] Figure 2 This is a block diagram of a unit module.

[0024] Figure 3 This is a waveform diagram of the synchronization signal used in this invention.

[0025] Figure 4 This is a flowchart of the initial startup method of a semiconductor transformer according to a preferred embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures

[0027] 10: Semiconductor transformer; 20: Synchronization controller

[0028] 10⁻¹, 10⁻², 10⁻³…10⁻ⁿ: Unit modules

[0029] 11: Drive unit 12: Rectifier

[0030] 13: Converter Detailed Implementation

[0031] To fully understand the structure and effects of the present invention, preferred embodiments are described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below and can be implemented in various forms and with various modifications. This description of embodiments is intended to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art. In the accompanying drawings, for ease of explanation, the constituent elements are shown enlarged, and the proportions of each constituent element may be enlarged or reduced.

[0032] The terms "first," "second," etc., can be used to describe various constituent elements, but the constituent elements are not limited to the above terms. The above terms are only used to distinguish one constituent element from another. For example, without departing from the scope of the invention, "first constituent element" can be named "second constituent element," and similarly, "second constituent element" can be named "first constituent element." Furthermore, unless otherwise stated, singular expressions include plural expressions. Unless otherwise defined, the terms used in the embodiments of the present invention can be interpreted as having meanings commonly known to those skilled in the art.

[0033] Hereinafter, with reference to the accompanying drawings, a specific description will be given of an initial start-up device and method for a semiconductor transformer according to an embodiment of the present invention.

[0034] Figure 1 This is a block diagram of a semiconductor transformer initial start-up device according to an embodiment of the present invention.

[0035] Reference Figure 1 The present invention may include: a plurality of power conversion unit modules 10-1, 10-2, 10-3...10-n connected in series with respect to the primary voltage and sequentially converting the primary voltage; and a synchronization controller 20 providing start signals and synchronization signals to the plurality of power conversion unit modules 10-1, 10-2, 10-3...10-n.

[0036] The power conversion unit modules 10-1, 10-2, 10-3...10-n can each include various internal configurations depending on the structure of the semiconductor transformer.

[0037] For example, each unit module may include an AC / DC rectifier and a DC / DC converter, which can be used to convert the DC voltage of the AC / DC rectifier into a low-voltage DC voltage for supply.

[0038] If AC voltage needs to be supplied on the secondary side, a hybrid power distribution system structure with an additional DC / AC inverter on the secondary side can be used.

[0039] Thus, power conversion unit modules 10-1, 10-2, 10-3...10-n with various structures are connected in series with respect to the primary voltage AC. Hereinafter, the power conversion unit module can be simply referred to as a "unit module".

[0040] Figure 2 This is a block diagram of unit module 10-1.

[0041] Reference Figure 2The unit module 10-1 used in this invention includes a drive unit 11, which drives the switches constituting the rectifier 12 and the converter 13 according to a synchronization signal provided from the outside (synchronization controller 20).

[0042] Although Figure 2 An example of a unit module 10-1 is shown, but other unit modules 10-2, 10-3...10-n also use the same structure.

[0043] The rectifier 12 and converter 13 can respectively use an AFE rectifier and a plurality of full-bridge converters. In this case, the inputs of the full-bridge converters are connected in series and the outputs are connected in parallel.

[0044] Thus, rectifier 12 and converter 13 each include switches as multiple switching devices, and unit modules 10-1, 10-2, 10-3...10-n each synchronously control the opening and closing of multiple switching devices.

[0045] In addition, the drive unit 11 performs control for each of the starting unit modules 10-1, 10-2, 10-3...10-n.

[0046] Refer again Figure 2 A link capacitor C is included between the rectifier 12 and the converter 13. The drive unit 11 performs charging control on the link capacitor C before the actual driving of the semiconductor transformer so that it can reach the initial reference value.

[0047] At this point, the link capacitor C can be charged using rectifier 12 or by using an additional charging circuit.

[0048] That is, the drive unit 11 performs the function of charging the link capacitor C for the synchronous control of the rectifier 12 and the converter 13 and the start-up of the semiconductor transformer. In the prior art, a start-up signal for starting is provided separately from the synchronization signal from the outside.

[0049] Therefore, although an additional communication interface is used to apply the start command, there is a problem that it is difficult to start each of the unit modules 10-1, 10-2, 10-3...10-n at the same time, depending on the different data processing methods or data processing speeds of the unit modules 10-1, 10-2, 10-3...10-n.

[0050] The present invention can use the synchronization signal of the synchronization controller 20 as the start command instead of an additional start command.

[0051] Figure 3 This is a waveform diagram of the synchronization signal used in this invention.

[0052] Reference Figure 3The synchronization signal can be a square wave. The synchronization controller 20 outputs the same synchronization signal to the respective drive units 11 of the unit modules 10-1, 10-2, 10-3...10-n.

[0053] The drive unit 11 performs switching control of the rectifier 12 and the converter 13 by detecting the rising edge of the synchronization signal.

[0054] At this time, if the rising edge of the square wave is detected, the drive unit 11 can identify it as a start signal.

[0055] That is, the drive unit 11 determines the rising edge of the square wave of the synchronization signal from the synchronization controller 20 as a start command and a synchronization signal, and performs the action of charging the link capacitor C. That is, it performs the start operation.

[0056] Then, the drive unit 11, which detects the rising edge of the second square wave of the subsequently input synchronization signal, determines it as a synchronization signal and controls the switching of the rectifier 12 and the converter 13.

[0057] Therefore, the present invention enables multiple unit modules 10-1, 10-2, 10-3...10-n to start up simultaneously and coordinate their actions, thus achieving stable operation of the semiconductor transformer.

[0058] Figure 4 This is a flowchart of the initial startup method of a semiconductor transformer according to a preferred embodiment of the present invention.

[0059] Reference Figure 4 The present invention includes: if a rising edge of a synchronization signal is detected, a step of confirming whether the current state is a synchronization control state (S41); if the state is a synchronization control state, a step of performing synchronization control synchronously with the rising edge of the synchronization signal (S42); if the state is not a synchronization control state, a step of determining it as a start command and charging the link capacitor C (S43).

[0060] The above steps are the processes processed in the drive unit 11, which is composed of each of the unit modules 10-1, 10-2, 10-3...10-n. The synchronous control state indicates the state in which the drive unit 11 controls the switching of the rectifier 12 and the converter 13.

[0061] That is, the present invention can control all the unit modules 10-1, 10-2, 10-3...10-n to simultaneously become start-up state by detecting the rising edge of the synchronization signal input from the synchronization controller 20 as a start command.

[0062] At this time, if all unit modules 10-1, 10-2, 10-3...10-n are operating, the rising edge of the synchronization signal becomes the opportunity to achieve synchronization. If each unit module 10-1, 10-2, 10-3...10-n is not operating, it is detected as a start command and a synchronization signal.

[0063] Although the above example illustrates a square wave as the synchronization signal, its shape can vary as needed. It is not necessary to detect the rising edge; startup and synchronization control can be performed by detecting the point of change in the signal that is distinguishable from the previous state.

[0064] While embodiments of the present invention have been described above, these are merely illustrative, and those skilled in the art will understand that various modifications and equivalent embodiments can be achieved based on them. Therefore, the true scope of protection of the present invention should be determined by the appended claims.

[0065] Industrial applicability

[0066] This invention, as a technology that utilizes natural laws to control the initial startup of SST, has industrial potential.

Claims

1. An initial start-up device for a semiconductor transformer, characterized in that, include: A plurality of power conversion unit modules connected in series with each other; as well as A synchronization controller provides a synchronization signal with a set period to the plurality of power conversion unit modules, so that the plurality of power conversion unit modules operate according to the synchronization signal; Each of the power conversion unit modules, when not in operation, will determine the detected synchronization signal as a start signal and start.

2. The initial start-up device for a semiconductor transformer according to claim 1, wherein, The power conversion unit module includes a rectifier and a converter to convert power, and includes a drive unit that charges the link capacitor between the rectifier and the converter during startup.

3. The initial start-up device for a semiconductor transformer according to claim 2, wherein, The drive unit controls the switching of the rectifier or the switching of the converter according to the synchronization signal.

4. The initial start-up device for a semiconductor transformer according to claim 2, characterized in that, The drive unit charges the link capacitor by controlling the rectifier.

5. The initial start-up device for a semiconductor transformer according to claim 2, wherein, It also includes a charging circuit that charges the link capacitor according to the control of the drive unit.

6. A method for initial startup of a semiconductor transformer, the semiconductor transformer comprising a plurality of power conversion unit modules connected in series with each other, and a synchronization controller for synchronizing the operation of the plurality of power conversion unit modules by providing a synchronization signal of a predetermined period to the plurality of power conversion unit modules, wherein, The initial startup method includes: The step of determining whether there is a synchronization signal input from the synchronization controller in each of the plurality of power conversion unit modules; If a synchronization signal is input, then confirm whether the current plurality of power conversion unit modules are in operation, and if they are in operation, determine the step of the synchronization signal; and If it is not in operation, it is determined that the start command of each power conversion unit module is initiated, and the steps of each power conversion unit module are started.

7. The initial startup method for a semiconductor transformer according to claim 6, characterized in that, Each of the power conversion unit modules includes a link capacitor connecting the rectifier and the converter. The power conversion unit module is activated by charging the link capacitor.

8. The initial startup method for a semiconductor transformer according to claim 6, characterized in that, When the synchronization signal is input, if each of the power conversion unit modules is in operation, the power is converted synchronously with the synchronization signal.

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